Liev Schreiber – Shirtless Celebrity Studs

As you can see, Liev Schreiber is fit -- and as an added bonus, he adorably goes snorkeling with his children.

In order to get in tip-top shape to play Sabretooth in 'Wolverine,' Schreiber was inspired by internet commentary insulting his casting.

As he explained of the situation, “I started to read blogs in the comic world with things like ‘That’s the dumpiest, most out-of-shape Sabretooth I’ve ever seen in my life!’

"They gave me a muscle suit at the beginning. I was so humiliated I thought, I’ve got to try to do this on my own.”

To bulk up, co-star Hugh Jackman (you'll see him next on our list) put him on a poultry-excessive diet, prompting Schreiber to joke that they were "the Hitler and Mussolini of the chicken world."